Piston-packing expander



Sept. 3Q, 193$). HUEBER 1,7?7J43 PISTON PACKING EXPANDER Filed Feb. 18, v1928 Patented Sept. 30, M3

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HENRY HU'EBER, OF BUFFALO, NEW YORK, ASSIGNOR TO TRICO PRODUCTS CORPORA- TION, OF BUFFALO, NEW YORK PISTON-PACKING EXPANDER Application filed February 18, 1928.

This invention relates to a piston packing and primarily is designed for the packing of pistons in the vane type of pressure or socalled suction-operated windshield cleaner motors.

In the Vane type motor of suction-operated Windshield cleaners the piston comprises a pair of cupped leathers arranged edge to edge in opposition to each other, each leather packing member being clamped between a pair of fiat plates from which the marginal portions of the leather project for contacting with the walls of the motor chamber or cylinder. Each half or section of the vane piston comprises the cupped or flanged leather packing clamped between said pair of plates, and the two halves comprising the piston are secured to the opposite sides of the rock shaft which is j ournalled in the motor casing. The shaft as a rule is not packed about its journalled bearings so that atmospheric pressure may leak along the shaft and enteribetween the halves or sections of the piston thereby tending to hold the marginal flanges of the same outwardly against the walls of the piston chamber. The vane is also mounted on the shaft so as to extend above and below the same for eflecting a more efficient type of vane motor which-will be practically devoid of leakage about the piston from one side to the other. e

The thickness of the leather, the wear, and also the quality thereof determines more or less the thoroughness with which the leather packings prevent the leakage of atmospheric pressure thereaboutto the low pressure side. Also the wear and tear on the piston packing,

together with grease and oil collecting thereon when in use, will cause the leather packings to become set or to give up some of their inherent resiliency or yieldability so that the marginal portions will fail to bear evenly against the walls of the pistonchamber, therei by resulting in leakage and a consequential inefficiency in the operation of the windshield cleaner. In packing assemblies for fluid pressure motors of the positive pressure type, expanders of a rather stiif resilient metal have been incorporated to hold the leather flanges in contact with the cylinder walls. Obvious- Serial No. 255,489.

1y, these expander elements create additional friction to be overcome by the fluid pressure, which additional load is undesirable in suction-operated windshield cleaner motors since the available power is limited. Attempts have been made to weaken the spring pressure of such expanders by serrating the edges thereof thereby providing separate and independent tongues or small fingers which bear at spaced points on the marginal flanges of the leather packings. The serrated portions of such expanders do not provide uniform pressure on the leather packings continuously thereabout, and then too the serrations when of a stiff, resilient metal, will tend to cut into and wear through the leather and thereby impair its packing qualities. Furthermore, with expanders of a stiff, resilient metal the portions thereof which bear upon the marginal flanges or portions of the cupped leathers are pre-shaped or pro-formed so as to nest within the cupped leathers, necessitating further operation on the expander and resulting in additional expense in the production of the same. 7

The present invention has for its objects to provide a novel form of expander for the cup leathers of suction-operated windshield cleaner motors, affording light pressure to retain the marginal portions of the leather in constant and uniform contact with the walls of the piston chamber; to provide a packing expander which may be economically and ex-' peditiously produced, and without requiring any pre-formation; to provide a piston construction embodying a packing expander element which may be easily assembled and 'ing drawing,

casing of a windshield cleaner motor having a piston chamber with portlons of different 5 up of the former tyse of 1n windshield clea er motors of the fluid pres.

depicting, in section, a vane type piston embodying the improved piston packing expander, v l

Fig. 2 an inside elevation of one of the halves or sections of the vane piston,

Fig; 3 is a transverse sectional view through the free end portion of the assembled piston,

Fig. 4; is ai plan view of the improved packing expander element or plate, and

Fig. 5 is a sectional, dissembled perspective view of one piston section.

Referring more in detail to the accompanythe numeral 1' designates the radii, the larger chamber portion 2 constituting the pressurenpplication chamber in which the power is applied to the vane and the smaller chamber 3, which is formed above the shaft l, constituting the packing chamber and receiving portion of the piston or vane which extends above said shatt to provide an eficient and substantially leak-proof packing for the shaft in the casing.

The piston comprises two he ves or sec tions each consisting of an outer body plateh and an inner rigid body plate 6, an interposed cu'pper leather or packing member 7 and the improved packing expander 8, the parts 5, "1 constituting the makevane piston utilized sure type. lil hen the'inner and outer plates 5 and G and theint tuting the former typeof piston section, are assembled they'are secured together adjacent the outer ends ova fastening element such as a rivet 9, while their inner end portions are secured together by a common fas toning member 10 which extends completely through both sections of the piston and the interposed motor shaft 4 whereby the piston is firmly fixed to the shaft formovement therewith. The inner plates 6 of the piston sections may also be provided with'interlocking fingers or ears ll'adjacent their respective fastenings 9 to maintain the piston sections in a definite relation. The marginal portionsor flanges 12 of the leather packings ex tend beyond the margins of the inner and outer body plates 5 and 6 and turn towar each other so that suction maintaining in the chambers 2 and 3 at either side of the pis- "ton willitend to urge the adjacent flanges 12 outwardly into sealing relation with the inner walls of said. chambers.

Each leather expander plate 8 1s of very thin resilient metal (the thickness being'exaggerated in the drawing) so as to exert ]11St suificient pressure on the packing flanges 12 as will be required to hold them out lightly against the walls oisaid piston chamber 2, 3. For example, when constructing the expander plates from spring brassthe thickness of each expander plate is approximately one- .posed packing Z, consth;

'cesses 8 for recelving said sha' d sections and act to assist thousandth of an inch, being almost foil-like or tinsel-like in thickness, whereby the expander. will possess suflicient inherent resiliency to lightly urge the packing flanges outwardly. The expander is lllSQllGCl'Wltll-- out pro-forming i. e. without bending the flanges 8,the same being flat and lying within the plane of the body portion thereof.

The mayor body portion of the expander plate is given reinforcement by the superimposed innerplate 6 the latter being nearly coextensive with the expander but leaving the marginal flanges 8..which constitute the ac tive portionsof the expander. From Fig. 46 it will be observed that the active portions or flanges 8 are continuous and uninterrupted 7 so as to exert uniform pressure on the packing flanges 12 whereby the latter will be urged into uniform and continuous contact with the inner walls of the piston chamber thereabout. Each flange 8 terminates short of the next adjacent flange, being substantially coextensive with the adjacent edge of the inner rigid plate, so that the flange will readily yield directly from the supporting edge said inner plate. This will also avoid any binding or interference between thejllanges at the corners. fhe corners of the packing flanges 12 are held outwardly into firm contact with the corners of the piston chamber by reason of the pulling tendency of the sides of said packing flanges. Where the longitudinal flanges 8 xtend across the motel shaft l they are interrupted or cut out to provide re- This ar- ::ran 'ement permits of the active .tlan es 8 2D x D on opposite sides of the il'lOllOllSlltlit exerting that same uniform pressure against the leathor or packing flanges 12 immediately adja cent the shaft as they do at" other points throughout their lengths.

In practice the shaft 4 is preferably flattened where it comes in eontact with the inner plates: 6 at opposite sides thereof, and immediately beyond the sides of said plates the shaft is provided with circular enlargements 4 designed for supporting the adjacent portions of the packing flanges 12 out wardly whereby any leakage of air alon the shaft hearings will enter between the piston the expanders in maintaining the packing flanges 12 firmly against the walls of the piston chamber.

In assembling each section of the piston, the inner and outer plates are arranged as heretofore, on opposite sides of the pre formed leather packing 7, and in addition the flat expander plate 8 is'inserted flat beneath the inner plate and without any pie-forming the flanges 8 yielding under tension as the body portion of the expander is forced inside the cupped leather upon securing the component parts of the piston section together by the fastener 9. Then, when thetwo piston sections are secured to the opposite sides of the shaft 4 by the fastener 10 the adjacent portion of the inner plate 6 will be brought firmly down against the expander and cause the adjacent flange portion 8 of the latter to be received within the adjacent portions of the flanges 12. As thus received by said flanges 12 the active portions 8 of the expander plates will be more or less conformable thereto but under a light tension suflicient to urge the flanges 12 into light but uniform and continuous contact with the walls of the piston chamber. Being inserted flat and then flexed by the flanges 12 said expander flanges 8 normally tend to return to the plane of the expander body and thereby urge said packing flanges out against the chamber walls. The fact that the expander plate is riveted or secured beneath the plate 6 prevents the same from creeping or shifting and produces an even and uniform expander action throughout.

Since the expanders do not require any preshaping, and being stamped of very light stock, said expanders may be very economically produced and their assembly with the companion parts of the piston very expeditiously effected. Since the active portions of the expanders are continuous and uninterrupted their action on the packing flanges 12 will likewise be continuous and uniform, and the packing flanges will not be subjected to a multiplicity of sharp, stiff edges which would otherwise tend to pierce and tear the fibre of said packing flanges and result in serious injury to and impairment of the same.

What is claimed is:

1. A vane type piston for windshield cleaner motors of the suction-operated type, comprising a supporting shaft and a piston section on each side thereof, each piston section comprising an outer rigid plate, an inner rigid plate, an interposed leather packing having extending marginal flanges cupped toward the companion piston section, an ex pander plate interposed between the inner rigid plate and said leather packing and having marginal active portions extending beyond the body lines of said inner rigid plate, said marginal active portions being received and shaped by the cupped marginal flanges of said leather packing, means securing said outer rigid plate, said inner rigid plate, said packing, and said expander plate together whereby the marginal active portions of the expander plate are substantially conformably received under tension by the cupped marginal flange portions of said leather packing, and means for connecting the piston sections to the shaft;

2. A vane type piston for windshield cleaner motors of the suction-operated type, comprising a supporting shaft, and a piston section on each side thereof, each piston section comprising an outer rigid plate,

an inner rigid plate, an interposed cupped leather packing having extending marginal flanges, an expander plate interposed flat between one of said rigid plates and said leather packing and having marginal portions extending beyond the body lines of said rigid plate and being received and shaped by the cupped marginal flanges of said leather packing, means securing said outer rigid plate, said inner rigid plate, said packing, and said ex- 7 pander plate together whereby the marginal ,active portions of the expander plate are substantially conformed under tension to the cupped marginal flanges of said leather packing, said means being disposed at a distance from said shaft, and means passing through the component parts ofeach piston section and through the shaft forsecuring said sections to said shaft.

3. A vane type piston for windshield cleaner motors of the suction-operated type, comprising a supporting shaft, and a piston section on each side thereof, each piston section comprising spaced rigid plates, an interposed leather packing having extending marginal flanges, an expander plate interposed between one rigid plate and said leather packing and having marginal portions extending beyond the body lines of said one rigid plate and being received and shaped by the cupped marginal flanges of said leather packing, means securing said rigid plates, said packing and said expander plate together whereby the marginal active portions of the expander plate are substantially conformed under tension to the cupped marginal flanges of said leather packing, said means being disposed at a distance from said shaft, the inner rigid plates of the two piston sections having interlocking parts adjacent said means, and means passing through the component parts of each piston section and through the shaft for securing said sections to said shaft.

4. A piston assembly for windshield 1W cleaner motors of the suction-operated type, comprising a cupped leather packing, an inner rigid plate, an outer rigid plate between which plates said cupped leather packing is received, an expander plate interposed be- H5 tween said inner rigid plate and said packing, said expander plate having active portions extending beyond the body lines of said inner rigid plate and normally tending to return to the body plane of said inner rigid 12 plate and shaped under tension by the flanges of said cupped leather packing.

5. A piston assembly for windshield cleaner motors of the suction-operated type, comprising a cupped leather packing, an inner rigid plate, an outer rigid plate between which plates said cupped leather packing is 4 received, a flat expander plate interposed between said inner rigid plate and said packing, said expander plate having active portions extending beyond the body lines of said inner rigid plate and flexed from the body plane of said inner rigid plate under tension by the flanges of said cupped leather packing, the marginal active portions of said expander plate being uninterrupted and continuous throughout their lengths and exert ing uniform pressure throughout on said flanges of the leather packing.

6. A vane type piston for windshield cleaner motors of the suction-operated type, comprising a supporting shaft, and a piston section on each side thereof, each piston section comprising an outer rigid plate, an inner rigid plate, an interposed leather packing having extending margin alflangescupped toward the companion piston section, an expander plate interposed between the inner rigid plate and said leather packing and having marginal portions extending beyond the body lines of said inner rigid plate and being received and flexed from the body plane of the expander plate by the cupped marginal flanges of said leather packing, means securing said outer'rigid plate, said inner rigid plate, said packing, and said expander plate together whereby the marginal active portions of the expander plate are substantially conformed under tension to the said cupped marginal flanges of said leather packing, the marginal active portions of said expander plates being continuous and uninterrupted throughout their lengths on opposite sides of said shaft, said marginal active portions being recessed to receive said shaft, and means for securing the piston sections to the op posite sides of the shaft.

7. An expander plate for cupped packing members, comprising a flat body of resilient metal and having marginal active portions in the plane of the body and flexible from the plane thereof solely by the flanges of an associated cupped packing member.

8. A piston assembly for fluid pressure motors, comprising a pair of rigid plates fixed intermediate their ends to opposite sides of the motor shaft and extending above and below the same, a cupped packing for each plate receiving the same between its flanges and extending across the shaft above and below the same coextensively with the plate, and an expander plate interposed between and secured against relative creeping to said rigid plate and packing and extending across the shaft above and below the same, said expander plate being secured within the cupped packing by its rigid plate and having continuous marginal flanges projccting from beneath the rigid plate and substantially coextensive with the edges thereof.

9. An expander plate for piston cupped packing, comprising a rectangular body, and marginal active flanges, each flange being continuous and substantially coextensive with the side of the body to which it is attached and terminating substantially in the planes of the adjacent sides of the body.

10. A packing device for vacuum actuated pistons, comprising a packing leather having a cupped margin, aflat resilient expander plate having its body and marginal portions normally in a common plane, and means for clampin said expander plate on said packing leat er whereby the marginal portions of said expander plate are flexed within said cupped margin from the plane of the body of the plate, said expander plate being of suflicient thinness to be thereby flexed without substantially distorting the said cupped margin.

11. A packing device for vacuum actuated pistons of polygonal form, comprising a flat polygonal expander plate having uninterrupted flanges on each of its sides and coextensive therewith, a packing leather of polygonal form having a cupped margin, and means for clamping said expander plate on said packing leather whereby the said flanges are flexed within said cupped margin.

HENRY HUEBER. 

